Power to a security light

[BigD]

Please can someone put me out of my misery? Been trying all weekend to suss this out. I want to take a fused spur from the garage 2 way light switch. This is wired as follows; red from 3 core & earth to 'common', red & blue together and black & yellow together.

Firstly, I presume I can 'tap into' the light switch to run a fused spur.

Secondly, what do I connect the red & black from the fused spur to?

 

[spark]

You presume wrong You'll need to take it from the light not the switch because your switch only has live conductors at it, not a neutral Wasted weekend then

 

[BigD]

Thanks Spark, thats the last time I take note of the guy from the local DIY shop If thats the case then, I take it I will run a twin & earth cable from the ceiling rose. I can't get to it from above the ceiling as it is an integral garage so I'll have to run the cable along the ceiling. As an alternative, I have a socket in the garage, but I think a spur has already been taken off it for the conservatory (3 cables in total). Is there any way I can take a feed of this? I also considered buying a 10m extension cable and plug the damm thing in Again, bloke at the DIY store said a fused spur was a better bet. Any thoughts on that idea?

 

[spark]

Yep you can take a feed off the socket to supply a fused connection unit (fused spur) and then connect both the conservarory and security light to the 'load' side of it, as long as you've considered whether or not your load will exceed the 13A in the spur. Or you can run a bit of mini-trunking across the ceiling (if it's only a garage it won't be too bad) from the ceiling rose.

 

[BigD]

I'm not sure about the socket. There are 2 cables running from it that I think the electrician from Conservatory firm has wired in. There are 3 double sockets in the conservatory. TV, video, light, wall heater etc. so I think I'm on thin ice with that Think I'll go for the ceiling rose with trunking, but may be lazy and use a long extension lead. Is that acceptable and would I need a special lead or will the fused plug provide required protection. Thanks for all your help.

 

[breezer]

i would have to slightly disagree. I would say why not put in another socket or spur and put that on the ring. (assuming the existing socket is in the ring) this is because although you could run 2 things from the load side of the spur if one goes they both go. by having 2 spurs (on the ring) you will only loose one should a problem occur.

You should also politley tell the bloke in the diy shop that altough his intentions were good, his advice is wrong and if that is the type of advice he gives he can be held liable if something should go wrong.

why not give him this url (web address) and let him see for himself

 

[BigD]

How can I tell by looking at the wiring at the socket whether it is in the ring and whether I can run a spur from it? If the socket only had 1 cable connected to it originally, would this indicate it is not in the ring? It now has 3 cables, does this mean there are 2 spurs, one for the lights and one for the sockets in the conservatory? If so, can I run a 3rd spur from it? I have read you can't, if not what options would I have here then?

Sorry for all the Qs, this is my first attempt at electrical diy

 

[breezer]

How can I tell by looking at the wiring at the socket whether it is in the ring and whether I can run a spur from it? If the socket only had 1 cable connected to it originally, would this indicate it is not in the ring? It now has 3 cables, does this mean there are 2 spurs, one for the lights and one for the sockets in the conservatory? If so, can I run a 3rd spur from it? I have read you can't, if not what options would I have here then?

Sorry for all the Qs, this is my first attempt at electrical diy

you are right on most counts, and no you can not run another spur from it. (there is one too many as it is)

where is it fed from and what size of cable as you may be able to put in a small consumers unit. if not a bigger cable will need to be installed

 

[spark]

I was going to ask you that...I wondered how you had 3 cables and two were used for the conservatory. Looks like Mr Conservatory has been naughty. You say the lights are spurred from the socket? Without a fused spur? I'd say it's more than one too many...if that socket is itself a spur, then the fact you've got a further two cables from it makes it two too many.

 

[BigD]

I'm guessing that the 2 'new cables' are lights and sockets. There is no fused spur plate on the wall, just a 2 gang switch (light and fan). It is a new house, so is it likely that the socket in a garage is not on the ring? Is this referred to as 'radial'? If so, does this mean you can run several spurs from it? What other reasons could there be for the 2 new cables?

 

[spark]

Are the two new cables the same size? What size are they? It's possible it's a radial but unlikely in a house. What number and size breakers have you got in your consumer unit? I would say fitting a smaller consumer in place of the socket is unlikely to be an option though whether it's a spur from a ring or a radial.

 

[BigD]

I'll have a look tomorrow and post back. Too cold to go outside now!

Re consumer unit - is this the 'fuse box'? There are 6 x 230 (cooker, up sockets, down sockets, down lights x2, up lights). Is this what you meant?

 

[breezer]

it is what spark was refering to. ideally you should have a separate supply for a garage. lets wait and see what spark is thinking of

 

[BigD]

The 2 new cables are 2.5mm twin & earth. I have just finished wiring the fused spur to the ceiling rose and everything works Its only taken 3 days and 4 visits to the DIY shop/Focus Any thoughts spark on what I've done and how the garage socket is wired?

 

[spark]

Fused spur to the ceiling rose? If you've come from the ceiling rose to supply the security light there was no need for the fused spur because the MCB protecting the lighting circuit will already be suitable, probably 6A or 10A.

As for the garage socket, it will be a spur from the ring, not a radial. That's the reason I asked about the circuits in your consumer unit. You only have two rings and no radial circuits designated to the garage. As breezer said, a circuit for the garage would have been ideal but that's life, unless it's possible to run a separate supply to the garage? What you have now is two spurs from a spur, which is not good. I hate to be harsh, but I really hate bodge-it-yourself kitchen fitters, bathroom fitters, conservatory fitters....... . As has been mentioned before, they've seen it done once or twice and think it's so easy. It's different for the DIYer in that he's not charging anyone to bodge it and only has himself to blame if it goes wrong.....anyway, rant over.

Because you've got spurs from a spur you could pull excessive current through the spur leg of 2.5mm T&E without anything protecting the spur leg. It may be unpractical, but you really need to restrict the amount you can pull off the ring through the spur leg by fitting a fused connection unit in place of the socket in the garage and connecting everything else to the load side. Though you are replacing the socket with a fused connection unit, you can reconnect the socket on the load side of the fused connection unit. It's not ideal, but it's better than unsafe. It's the only way I can see other than running a new supply out.